在部分时候 Message Mapping 没那么好用，如：需要Rest XML时，可使用 IA 的转换规则，操作如下

大概流程

手写转换规则（同SAP STRANS的方法）
将转换规则打包为zip
上传转换规则
更改 Operation Mapping 的 Mapping Program 的类型为 XML

选择上传的xml转换程序

具体步骤

01 手写转换规则

示例如下:

- ABAP TO XML

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version='2.0' xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" version="1.0" encoding="utf-8" indent="yes" />
  <xsl:strip-space elements="*" />
  <xsl:template match='mt_zfi010_req'>
      <ufinterface>
          <xsl:attribute name="roottag">
              <xsl:value-of select="UFINTERFACE/ROOTTAG" />
          </xsl:attribute>
          <xsl:attribute name="account">
              <xsl:value-of select="UFINTERFACE/ACCOUNT" />
          </xsl:attribute>
          <voucher>
              <xsl:attribute name="id">
                  <xsl:value-of select="ID" />
              </xsl:attribute>
              <voucher_head>
                  <pk_accountingbook>
                      <xsl:value-of select="VOUCHER_HEAD/PK_ACCOUNTINGBOOK" />
                  </pk_accountingbook>
                  <memo1>
                      <xsl:value-of select="VOUCHER_HEAD/MEMO1" />
                  </memo1>
                  <memo2>
                      <xsl:value-of select="VOUCHER_HEAD/MEMO2" />
                  </memo2>
                  <reserve1>
                      <xsl:value-of select="VOUCHER_HEAD/RESERVE1" />
                  </reserve1>
                  <reserve2>
                      <xsl:value-of select="VOUCHER_HEAD/RESERVE2" />
                  </reserve2>
                  <details>
                      <xsl:for-each select="VOUCHER_HEAD/DETIALS">
                          <item>
                              <detailindex>
                                  <xsl:value-of select="DETAILINDEX" />
                              </detailindex>
                              <globalcreditamount>
                                  <xsl:value-of select="GLOBALCREDITAMOUNT" />
                              </globalcreditamount>
                              <ass>
                                  <xsl:for-each select="ASS">
                                      <item>
                                          <pk_Checktype>
                                              <xsl:value-of select="PK_CHECKTYPE" />
                                          </pk_Checktype>
                                          <pk_Checkvalue>
                                              <xsl:value-of select="PK_CHECKVALUE" />
                                          </pk_Checkvalue>
                                      </item>
                                  </xsl:for-each>
                              </ass>
                          </item>
                      </xsl:for-each>
                  </details>
              </voucher_head>
          </voucher>
      </ufinterface>
  </xsl:template>
</xsl:stylesheet>

- XML TO ABAP

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version='2.0' xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" version="1.0" encoding="utf-8" indent="yes" />
  <xsl:strip-space elements="*" />
  <xsl:template match='ufinterface'>
      <mt_zfi010_res>
          <UFINTERFACE>
              <ROOTTAG>
                  <xsl:value-of select='@roottag' />
              </ROOTTAG>
              <SENDER>
                  <xsl:value-of select='@sender' />
              </SENDER>
              <SUCCESSFUL>
                  <xsl:value-of select='@successful' />
              </SUCCESSFUL>
              <SENDRESULT>
                  <RESULTDESCRIPTION>
                      <xsl:value-of select='sendresult/resultdescription' />
                  </RESULTDESCRIPTION>
                  <CONTENT>
                      <xsl:value-of select='sendresult/content' />
                  </CONTENT>
              </SENDRESULT>
          </UFINTERFACE>
      </mt_zfi010_res>
  </xsl:template>
</xsl:stylesheet>